The present invention relates to rotors for caliper disc brakes and the like, and in particular to such rotors having a laminated construction.
Rotors are generally well known in the art, and are used extensively in caliper disc brakes, power transmission devices, clutches, and other similar machinery and mechanisms. Conventional rotors are formed of a radially inner hub or hat section having a central mounting face for mounting the rotor on an associated drive member, with an outer friction portion extending from the cylindrical hat wall. The outer friction portion includes a pair of opposite, flat annular friction surfaces adapted to interface with associated friction members, such as brake pads. The outer friction portion of the rotor may be vented or solid.
Brake rotors are typically cast from a ferrous material such as grey iron, and then are machined in multiple operations to shape the rotor, and form the opposite friction surfaces which interface with associated brake pads. Cast aluminum rotors are available to reduce the weight and corrosion problems associated with ferrous metal rotors, although the heat resistance and brake surface toughness of cast aluminum is typically less desirable than that of other types of rotors.
In addition, there are some composite rotors, in which different portions of the rotor are formed of different materials. For instance, the Ihm U.S. Pat. No. 5,509,510 discloses a composite rotor having combination of separate components including a friction portion formed of an aluminum metal matrix composite and a hub portion comprised of aluminum.
While the conventional rotors function in an effective manner, one of the problems associated with such brake rotors is the transmittance of noise which is audible to vehicle operators. It would therefore be desirable to provide an improved rotor which results in the reduction of noise while maintaining the desired braking performance.